Boron Nitride Nanoparticles Research Articles

Efficacy of Green and Chemically Synthesized Nano Boron Nitride on Sunflower Germination

ABSTRACTThis study explores the eco‐friendly synthesis of nanoparticles using natural sources, specifically employing Cassia fistula leaf extract for the production of boron nitride nanoparticles. Characterization of the synthesized nanoparticles was performed using Raman spectroscopy and UV‐visible spectroscopy to identify functional groups. Ab initio studies were conducted to investigate the electronic properties of the boron nitride nanostructures. The structural analysis through powder x‐ray diffraction confirmed a hexagonal configuration of the nanoparticles. Scanning electron microscopy and transmission electron microscopy revealed particle sizes below 100 nm. Laboratory experiments demonstrated that sunflower seeds treated with 1500 ppm of green‐synthesized nano boron nitride achieved the highest germination rate of 98.2%, surpassing other concentrations and chemically synthesized nanoparticles, which reached 93.9% at 2000 ppm. The control treatment yielded a germination rate of 76.2%. The eco‐friendly synthesized nanoparticles exhibited superior efficacy compared to both chemically synthesized nanoparticles and conventional fertilizers.

Hexagonal BN/Methylene Blue Heterostructures for Local Photodynamic Therapy of Melanoma

Melanoma is the most aggressive form of skin tumor and leads to a high mortality (5.0–5.6 %) among all cancers. To increase efficiency of its treatment during local photodynamic therapy (PDT), we developed h-BN/n·MB heterostructures based on hexagonal boron nitride (h-BN) nanoparticles (NPs) and adsorbed methylene blue (MB) of various concentrations (n). Heterostructures containing 200 mg of MB per 1 g of h-BN (h-BN/200 MB), after their irradiation with an artificial sunlight source for 30 min, generated 3.7 × 10−2 ± 0.2 × 10−3 μM × μg−1 of reactive oxygen species (ROS) and reduced the viability of A-375 melanoma cells by 90 % after 48 h. The observed levels of oxidative and antitumor activity of the h-BN/200 MB hybrid material significantly exceed those of the individual system components, MB and h-BN. It is shown that MB adsorbed on h-BN NPs possesses enhanced stability and photooxidative activity. Adsorbed MB has almost not the dark phototoxicity inherent in the MB solution and demonstrates enhanced biocompatibility with normal fibroblasts Wi-38. The results demonstrate the promising potential of h-BN/n-MB heterostructures for melanoma PDT.

Synthesis, Microstructural Investigation, and Mechanical Behavior of AA5083/Boron Nitride Nanocomposite

The as‐received aluminum alloy (AA5083) powders (44 μm) and hexagonal boron nitride (BN) nanoparticles (65–75 nm) are used to fabricate AA5083‐BN nanocomposites with varying BN content (0, 3, 6, 9, and 12 wt%). A powder metallurgy solid‐state method is employed, involving ball milling for 20 h at 100 rpm with a ball‐to‐powder mass ratio of 10:1. The processed powders are then consolidated through forging–sintering at 550 °C for 30 min, followed by hot forging at 225 MPa. The microstructure is examined using X‐ray diffraction, scanning electron microscopy, energy‐dispersive X‐ray, transmission electron microscopy, and electron backscatter diffraction to understand the effect of processing variables. The compaction behavior is investigated both experimentally and empirically, revealing a relative green density exceeding 88% at 500 MPa. The empirical models display coefficients of determination (R2 values) exceeding 99% for predicting the compaction behavior. Compression tests on bulk samples show that BN reinforcement significantly enhances ultimate compressive strength, with values reaching 473.256 ± 5.54, 536.374 ± 2.87, 567.694 ± 4.22, and 601.911 ± 6.54 MPa for TRB‐3, TRB‐6, TRB‐9, and TRB‐12, respectively. The developed composites achieve relative densities greater than 97%, indicating promising applications in the aerospace, automotive, and marine industries.

A wave-transparent electrothermal sandwich composite for high-efficient anti-icing/de-icing

Light-weight composite materials with multifunction are widely used on aircrafts, antennas and wind turbines. Its anti-icing/de-icing is still a great challenge due to its poor heat transmission and low heat resistance. To address these issues, a novel electrothermal sandwich composite (NESC) was prepared by hot pressing an electrothermal film into load-bearing composite materials. By optimizing the ingredient of boron nitride nanoparticle, the heat diffusion rate was improved by 86 %, saving ∼14 % of energy consumption for complete anti-icing in dynamic icing conditions compared to samples without thermal conductivity enhancement. Furthermore, high electromagnetic transmittance up to 80 % of NESC was ensured through electromagnetic design. Besides the high-efficient and electromagnetic compatible anti-icing performance, NESC also performs high resistance to acid/alkali, abrasion and impact, good heating uniformity, stable photothermal effect, and potential of large-area manufacture. This paper presents a promising solution for durable, multi-functional, compatible, and energy-saving composites for anti-icing and de-icing.

The process of evaporation of a colloidal solution of stabilized Boron nitride nanoparticles

Purpose. Characterization of the chemical structure of boron nitride nanoparticles by IR spectroscopy during the evaporation of their colloidal system and their sizes by small-angle X-ray scattering.Methods. The solvent evaporation process from the colloidal system was studied using a Nicolet iS 50 FT-IR spectrometer in the mid-IR range (400 – 4000 cm-1), with an attenuated total reflectance accessory with a diamond crystal (incident angle of 45°) and a liquid cell (200 μL). The sizes of the colloidal particles were determined using an smallangle X-ray scattering diffractometer in linear collimation mode (resolution 0.03 nm-1, copper anode X-ray tube 2.2 kW, λ = 0.154 nm, exposure time 30 s).Results. The IR spectrum of boron nitride nanoparticles powder was measured, containing lines characteristic of cubic (952 cm-1) ) – c-BN and hexagonal crystalline phases (758, 1301, and 1372 cm-1) – h-BN. The average size of boron nitride nanoparticles in the colloidal system, according to small-angle X-ray scattering data, was 46 and 84 nm. The size of stearic acid, which acts as a stabilizing shell, was 0.8, 1.3, and 2.5 nm. Analysis of the IR spectra showed complete evaporation of the solvents (hexane and chloroform) from a drop of colloidal solution 1.2 mm thick within 30 minutes.Conclusion. In this work, the average sizes of boron nitride nanoparticles stabilized with stearic acid in a colloidal system were determined and the process of its evaporation was studied.

Thermally conductive phase change nanocomposites presenting PS-PEG/SeO2 and PS-PEG/BN/SeO2

The phase change and thermal conductivity properties of nanocomposite materials consisting of cross-linked Poly(Styrene-block-Ethylene Glycol Dimethyl Methacrylate) (PS-PEG DM), boron nitride (BN), and selenium dioxide (SeO2) were investigated in this study. The different content of phase-changed materials (PCM) nanocomposites was prepared by using the hydraulic pressure technique. Promising melting enthalpy values (104.5, 98.8 and 165.8 J g−1) have been reached for P1Se3, P2BN2Se2, and P3BN2Se2 PCM nanocomposites. The enthalpy efficiencies associated with the processes of melting and freezing, denoted as λm and λc, respectively, were determined by the analysis of data obtained from DSC. Our study was demonstrated to present comprehensive information on the PS-PEG/BN, PS-PEG/SeO2, and PS-PEG/BN/SeO2 phase change nanomaterials, thereby facilitating their potential applications in various fields. The phase change and thermal conductivity properties of PS-PEG/BN/SeO2 nanocomposites were investigated. The incorporation of SeO2 and BN nanoparticles significantly enhanced the thermal conductivity (for P2BN4Se5), reaching values up to 8.277 W m−1 K−1. The λm values of P1Se3, P2BN2Se2, and P3BN2Se2 were calculated as 68.79, 61.23, and 87.86, respectively. The λc values of P2Se3; P1BN2Se2 were also calculated at 70.10; 98.93 and 161.92, respectively.

Optimization of UV-Curable Polyurethane Acrylate Coatings with Hexagonal Boron Nitride (hBN) for Improved Mechanical and Adhesive Properties.

Polymer coatings are widely used in industries for protection, decoration, and specific applications, typically including volatile organic compounds (VOCs) to achieve low viscosity. The growing environmental concerns and the anticipated limits on fossil feedstock have driven the coating industry towards eco-friendly alternatives, with UV-curing technology emerging as a promising solution due to its energy efficiency, low-temperature operation, reduced VOC emissions, and high curing speed. Polyurethane acrylates (PUAs) are critical in UV-curable formulations, offering excellent flexibility, impact strength, optical, and adhesion properties. However, UV-cured PUA coatings face limitations in thermal stability and tensile strength, which can be addressed by incorporating fillers. This study investigates the effects of multi-functionalized hexagonal boron nitride (hBN) nanoparticles on the mechanical, thermal, optical, and adhesion properties of UV-cured PUA films and coatings for pre-coated metals. The results demonstrated that incorporating hBN nanoparticles enhanced the mechanical and thermal properties of the nanocomposite films, with optimal performance observed at 0.5% hBN loading. Despite the improved properties, the FTIR spectra indicated that the low concentration of hBN did not produce significant changes, potentially due to the overshadowing signals from the difunctional polyurethane acrylate.

Novel approach to corrosion resistance and radiative cooling with biomimetic amorphous coatings

To address the application challenges of high-power-density electronic devices in harsh conditions, it is crucial to develop electric insulation materials that possess both corrosion resistance and excellent radiative cooling performance. In this study, inspired by the wrinkle morphology of the Camponotus ant with thermoregulation, a biomimetic amorphous coating composed of a hemispherical array was fabricated on aluminum alloy using plasma electrolytic oxidation (PEO) technology. This biomimetic microstructure is obtained by controlling the content of hexagonal boron nitride (h-BN) nanoparticles in the electrolyte, where the increase in current density at a later stage allows the transition of the porous coating to the hemispherical array. The effects of functional group vibration and rotation in combination with the hemispherical structure afford the biomimetic coating a high emissivity of 0.91 within the range of 3–14 μm, which reduces the LED temperature by 17.1 °C and achieves a cooling efficiency of 10.6 %. Meanwhile, with a resistivity of 5.15 × 1014 Ω∙cm and a dielectric strength of 29.9 V/μm, the coating can prevent current leakage, consequently improving the stability and reliability of electronic packaging materials. In addition, h-BN flakes in the biomimetic coating with almost defects free act as a protective barrier to enhance the corrosion resistance of the aluminum alloy. This approach offers a time-efficient and cost-effective route for the manufacture of multifunctional coatings with potential applications in electronic packaging.

Study of hybrid nanoscatterer for enhancing light efficiency of quantum dot-converted light-emitting diodes

Optical scatterer additives play a critical role in enhancing the light conversion efficiency and uniformity of quantum dot-converted light-emitting diodes (Qc-LEDs). This study investigates the impact of optical characteristics and morphology of nanoscatterer on the light conversion and extraction efficiency of Qc-LEDs. Various metal oxides and boron nitride nanoparticles and nanoplates with different diffraction index were selected to carry out the study. Finite-Difference Time-Domain (FDTD) simulation was employed to evaluate the scattering effect of various nanosphere and nanoplate scatterers on the optical performance of the Qc-LEDs. The simulation results revealed that the hybrid nanoscatterer integrates the forward-scattering from the nanosphere and backward-scattering of blue light from the nanoplate. Spectral analysis was conducted to examine the optical performance of Qc-LEDs with varying combinations and concentrations of nanoscatterers. TiO2 nanoparticles and Al2O3 nanoplates were found to be the best combination for maximal light conversion and extraction efficiency within Qc-LEDs. The results indicate an optimal light efficiency is obtained with the optimal ratio of 1:2:2 for quantum dots, TiO2 nanoparticles, and Al2O3 nanoplates. These findings reveal the relationship between optical properties, morphology, and light conversion efficiency in Qc-LEDs, highlighting the advantages of the hybrid nanoscatterers for improving optical performance of Qc-LEDs.

HBN/PVDF‐HFP and BNNS/PVDF‐HFP nanocomposites as flexible and lightweight dielectric capacitors: High energy storage performance via electrically insulating nanoparticles

AbstractAs the energy demand continuously increases, polymer‐based materials have attracted much attention for energy storage systems as dielectric capacitors due to their higher power density and charge–discharge rate than lithium‐ion batteries and supercapacitors. However, it is necessary to increase the energy density of dielectric capacitors. In this context, poly(vinylidene fluoride‐co‐hexafluoropropylene), PVDF‐HFP, matrix nanocomposites are produced by solution casting method reinforced with hexagonal boron nitride (hBN) nanoparticles and silane‐modified boron nitride nanosheets ‐BNNSs‐ (BNNS‐VTS) up to 10 wt.% filler content. The effects of filler content and surface modification of hBN/BNNSs on PVDF‐HFP matrix nanocomposites' microstructure, phase evolution, crystalization behavior, dielectric properties, and energy storage performance are discussed. 4% hBN/PVDF‐HFP nanocomposite demonstrates 641 MV·m−1 of breakdown strength and 23.2 J·cm−3 of discharged energy density due to hexagonal boron nitride's excellent electrical insulating behavior. The achieved values are 3.0 and 10.5 times superior to the values of the neat thin film, respectively, and they are noteworthy among hBN‐ or BNNS‐reinforced PVDF‐based nanocomposites, even in multi‐layered structures. Furthermore, 4% hBN/PVDF‐HFP presents a giant charge–discharge energy efficiency (92%). It is thus demonstrated that hBN/PVDF‐HFP nanocomposites hold a great potential to be used in energy storage applications as flexible and lightweight dielectric capacitors.Highlights PVDF‐HFP matrix nanocomposites for electrical energy storage as flexible dielectric capacitors hBN NPs and silane‐modified BNNSs are reinforced into the matrix by 0–10 wt.%. The effects of filler content and surface modification of hBN/BNNSs are discussed. 4% hBN loading results in 23.2 J·cm−3 energy density and 92% efficiency at 641 MV·m−1 breakdown strength. Those metrics are relatively high in hBN‐ or BNNS‐reinforced PVDF‐based nanocomposites.

Molecular dynamics study of sintering of faceted cubic boron nitride nanoparticles at high temperatures

The sintering mechanisms and temperature dependence of coalescence of colliding cubic boron nitride (c-BN) nanoparticles are investigated using classical molecular dynamics (MD) simulation. Particle-particle collisions of 2.55-nm octahedral c-BN nanoparticles, consisting solely of the most stable {111} facets, with half of the surface terminations being boron and the other half nitrogen, are analyzed statistically and evaluated to assess the initial temperature range (2500 K – 3100 K) for sintering and its effect on grain growth. At these temperatures, the collision process maximizes contact surface area through interfacial sliding, thereby minimizing free energy and accommodating dangling bonds. Moreover, the exothermic formation of bonds of the coalescing nanoparticles increases the temperature. The alignment of the {111} orientation of the two collided nanoparticles occurs at a temperature slightly above the melting point, and rapid grain growth happens when the temperature is a few hundred degrees higher than that. However, phase separation also takes place at the corners away from the collision plane of the merging nanoparticles. Between 3100 K and 3250 K, crystalline alignment occurs, which aids the sintering process and allows for the formation of a well-structured nanocluster. However, above 3300 K, phase separation dominates and drives the melting of the entire sintered nanocluster.

Preparation of BN Nanoparticle with High Sintering Activity and Its Formation Mechanism.

Hexagonal boron nitride (h-BN) nanoparticles have attracted increasing attention due to their unique structure and properties. However, it is difficult to synthesize h-BN nanoparticles with uniform spherical morphology due to their crystal characteristic. The morphology control by tuning their precursor synthesis is a promising and effective strategy to solve this problem. Especially, the treatment temperature of precursors plays an important role in the morphology and surface area of h-BN nanoparticles. Herein, h-BN nanoparticles with different morphologies were synthesized via regulating the treatment temperature of precursors. The result shows that treatment temperature will affect the microstructure and state of precursor and further influence the morphology of h-BN products. Benefiting from the unique structure, the h-BN obtained using 250 °C precursors shows higher specific surface area (61.1 m2 g-1) than that of 85 °C (36.5 m2 g-1) and 145 °C (27.9 m2 g-1). h-BN products obtained using 250 °C precursors show higher specific surface area than that of 85 °C and 145 °C. The optimal condition for obtaining high-quality spherical h-BN is the pretreatment temperature of 250 °C and sintering temperature of 1300 °C. Importantly, compared with commercial h-BN nanoparticles, the synthesized h-BN nanoparticles show more uniform structure and larger specific surface area, indicating that sintering activity will be greatly improved. Furthermore, the reaction pathway and formation mechanism of h-BN was revealed by DFT calculations. The result shows that the five stationary states and five transition states exist in the reaction pathway, and the energy barrier can be overcome at high temperatures to form a ring h-BN. In view of its simplicity and efficiency, this work is promising for designing and guiding the synthesis of h-BN nanoparticles with uniform morphology.

Preparation and properties of poly (ethylene-co-vinyl acetate)/boron nitride nanocomposite for energy storage devices

A simple open-mill mixing approach was employed to develop thermally and mechanically stable nanocomposites consisting of poly (ethylene- co-vinyl acetate) (EVA) as the matrix and boron nitride (BN) as a reinforcing nanofiller. The development of nanocomposites was examined by FT-IR, UV spectroscopy, XRD, TEM, TGA and DSC. The attachment of BN to EVA was confirmed by the characteristic BN band at 602 cm−1 in the FT-IR spectra. The UV measurements revealed a red shift in the nanocomposites due to nanoparticle interactions with polymer chains and the bandgap energy decreased with the nanofiller concentration. The XRD TEM analysis indicated the presence of a crystalline BN phase in EVA. Enhanced thermal stability and glass transition temperature of the polymer with the addition of BN nanoparticles were revealed from TGA and DSC, respectively. The EVA with 5% BN nanocomposite was discovered to have higher mechanical properties, electrical conductivity and lower optical bandgap energy. The tensile strength, tear resistance, impact strength and hardness of EVA increased with the inclusion of BN, whereas elongation at break was reduced. The findings of the experiments showed that the EVA/BN nanocomposites would provide excellent options for mechanically and thermally stable materials for energy storage applications.

Injectable Boron Nitride‐Hyaluronic Acid Hybrid Hydrogels to Facilitate Joint Motion: Mechanical and Tribological Characterization

AbstractHexagonal boron nitride (hBN) is used as an additive in engineering applications such as polymers, ceramics, and coatings because of its anti‐wear and lubrication performance. It has a high potential as a biomaterial, but it has not been evaluated to facilitate joint motion with its lubricating properties until now. In this study, the hypothesis that boron nitride nanoparticles (BNPs) and nanosheets (BNNSs) can facilitate movement in the joint region is evaluated for the first time. Hyaluronic acid‐based hybrid hydrogels are designed to transport BN particles to the target area and pin‐on‐disc tests on cartilage pins paired with glass disks are conducted to determine the validity of the proposed hypothesis. The injectability, mechanical properties, and friction coefficients of hydrogels with the addition of increasing proportions of different hBN morphologies are monitored. As a result, hyaluronic acid has been found to be a suitable carrier for the injectability of boron nitride in biomedical applications. The amount and morphology of boron nitride are observed as two important parameters. A significant decrease in the friction coefficient (18.9%) is observed in the BNNS‐doped hybrid hydrogel compared to the virgin hydrogel. hBN can be considered as a new therapeutic agent with the potential to facilitate joint mobility.

Effects of Hexagonal Boron Nitride and Mesoporous Silica Nanoparticles on the Morphology, Mechanical Properties and Antimicrobial Activity of Dental Composites

Hexagonal boron nitride (HBN), an artificial material with unique properties, is used in many industries. This article focuses on the extent to which hexagonal boron nitride and silica nanoparticles (MSN) affect the physicochemical and mechanical properties and antimicrobial activity of prepared dental composites. In this study, HBN, and MSN were used as additives in dental composites. 5% and 10% by weight of HBN are added to the structure of the composite materials. FTIR analysis were performed to determine the components of the produced boron nitride powders, hexagonal boron nitride-containing composites, and filling material applications. The structural and microstructural properties of dental composites have been extensively characterized using X-ray diffractometry (XRD). Surface morphology and distributions of nano boron nitride were determined by scanning electron microscopy (SEM)-EDS. In addition, the solubility of dental composites in water and their stability in water and chemical solution (Fenton) were determined by three repetitive experiments. Finally, the antimicrobial activity of dental composites was detected by using Minimum Inhibitory Concentration (MIC) measurement, as well as Minimum Fungicidal Concentration (MFC) method against yeast strain Saccharomyces cerevisiae, and Minimum Bactericidal Concentration (MBC) method against bacteria strains, Staphylococcus aureus and Escherichia coli. Since the HMP series have better antimicrobial activity than the HP series, they are more suitable for preventing dental caries and for long-term use of dental composites. In addition, when HMP and HP series added to the composite are compared, HMP-containing dental composites have better physicochemical and mechanical properties and therefore have a high potential for commercialization.

Diclofenac enhances Boron nitride nanoparticle toxicity in freshwater green microalgae, Scenedesmus obliquus: Elucidating the role of oxidative stress

Boron nanoparticles have numerous medical, industrial, and environmental applications as potential nanomaterials. Given the inevitable release of these particles in aquatic environments, they can combine with other pollutants like pharmaceuticals. Therefore, it is necessary to investigate their combined detrimental effects on freshwater biota. This study examined the joint impacts of Boron nitride nanoparticles (BNNPs) and Diclofenac (DCF) on freshwater microalgae Scenedesmus obliquus. Three different concentrations of BNNPs (0.1, 1, and 10 mg L−1) were mixed with 1 mg L−1 of DCF and were treated with algal cells, and biochemical analyses were performed. A concentration-dependent decrease in algal cell viability was observed after a 72-h interaction period with BNNPs and their binary combinations. The maximum toxic effects were observed for the highest combination of BNNPs + DCF, i.e., 10 mg L−1 BNNPs + 1 mg L−1 DCF. Similarly, an increase in the oxidative stress parameters and antioxidant enzyme activity was observed, which correlated directly to the decline in cell viability. The algal cells also showed reduced photosynthetic efficiency and electron transfer rate upon interaction with BNNPs. The results of this research emphasize the importance of considering the negative consequences of emerging pollutants and their combinations with other pollutants, BNNPs, and DCF as part of a thorough evaluation of ecotoxicity in freshwater algal species.

Unraveling the Impact of Boron Nitride and Silicon Nitride Nanoparticles on Thermoplastic Polyurethane Fibers and Mats for Advanced Heat Management.

The urgent challenges posed by the energy crisis, alongside the heat dissipation of advanced electronics, have embarked on a rising demand for the development of highly thermally conductive polymer composites. Electrospun composite mats, known for their flexibility, permeability, high concentration and orientational degree of conductive fillers, stand out as one of the prime candidates for addressing this need. This study explores the efficacy of boron nitride (BN) and its potential alternative, silicon nitride (SiN) nanoparticles, in enhancing the thermal performance of the electrospun composite thermoplastic polyurethane (TPU) fibers and mats. The 3D reconstructed models obtained from FIB-SEM imaging provided valuable insights into the morphology of the composite fibers, aiding the interpretation of the measured thermal performance through scanning thermal microscopy for the individual composite fibers and infrared thermography for the composite mats. Notably, we found that TPU-SiN fibers exhibit superior heat conduction compared to TPU-BN fibers, with up to a 6 °C higher surface temperature observed in mats coated on copper pipes. Our results underscore the crucial role of arrangement of nanoparticles and fiber morphology in improving heat conduction in the electrospun composites. Moreover, SiN nanoparticles are introduced as a more suitable filler for heat conduction enhancement of electrospun TPU fibers and mats, suggesting immense potential for smart textiles and thermal management applications.

Improvement in Tribological Properties with Addition of Hexagonal Boron Nitride (h-BN) and Molybdenum Disulfide (MoS2) Nanoparticles in Aerospace Lubricants

In the aircraft mounted accessory gearbox and gas turbine engine gearbox, a significant rise in temperature of lubricant was consistently observed due to the high coefficient of friction (COF) between the moving parts. This phenomenon limits the speed and power transmission of the gearbox. To resolve this, the current study recommends adding specific nanoparticles (NP) as an additive to the military (MIL) grade lubricant to reduce frictional resistance between the gears. Surfactants were also added to hexagonal boron nitride (h-BN) and molybdenum disulfide (MoS2) nanolubricants (NL) to improve NP suspension. Tribological investigations were conducted with a four-ball tester, a shear stability tester, and a Reichert tester to examine the lubricants. During the four-ball test, the wear scar diameter (WSD) on the specimen decreased by 16.73% and 12.3% with h-BN and MoS2 NL, respectively, compared to the results obtained using the base lubricant (BL). In the shear stability test, h-BN NL demonstrated 93%, and MoS2 NL demonstrated 67% more shear stability than the BL, while the COF was reduced by 13% in both h-BN and MoS2 NLs during the Reichert test. These test results prove that h-BN and MoS2 NPs, when added to a MIL standard BL, can demonstrate improved tribological capabilities even at extreme operational conditions.

Assessment on thermophysical properties of nano enhanced heat transfer fluid with hexagonal boron nitride nanoparticles for thermal management of photovoltaic thermal (PVT) system

One of the most promising sources of energy to meet demand and reduce pollution from fossil fuels is solar energy. To maximize energy conversion, solar technology efficiency, whether it comes from thermal systems, photovoltaic panels, or a hybrid known as photovoltaic-thermal (PVT) systems is critical. This work looks into the formulation and thermophysical of hBN-water nanofluids, with an emphasis on how they might be used as coolants in PVT systems to improve electrical performance. After a meticulous preparation process, the nanofluids exhibited exceptional stability, confirmed through visual inspection and zeta potential evaluation. Zeta potential analysis revealed consistent values across different temperatures and volume concentrations. Density decreased with temperature, while viscosity increased with volume concentration but decreased with temperature. Thermal conductivity showed a consistent increase with volume concentration and temperature. Through optimization, the 0.5 vol% concentration was identified as optimal for the PVT system. Compared to no coolant and water-based coolant scenarios, hBN-water nanofluids effectively regulated cell temperatures between 40.25°C and 46.34°C, demonstrating superior thermal conductivity and heat transfer properties. Moreover, the nanofluid coolant enhanced the PVT system's electrical performance. Open circuit voltage remained consistent (19.67 V to 20.81 V), short circuit current and output power improved with higher irradiance levels, and electrical efficiency, thermal efficiency and overall efficiency reached 5.73–5.88 %, 54.15–62.73 % and 59.88–68.62 % respectively These findings underscore the potential of hBN-water nanofluids in enhancing thermal management and electrical performance in solar energy systems. By minimizing thermal losses and maximizing electrical output, nanofluid coolants offer promising avenues for optimizing the efficiency of renewable energy technologies.

An Amphiphilic Surface with Improved Thermal Radiation for Water Harvesting.

Water scarcity poses a significant challenge for people living in arid areas. Despite the effectiveness of many bioinspired surfaces in promoting vapor condensation, their water-harvesting efficiency is insufficient. This is often exacerbated by overheating, which decreases the performance in terms of the micro-droplet concentration and movement on surfaces. In this study, we used a spotted amphiphilic surface to enhance the surfaces' water-harvesting efficiency while maintaining their heat emissivity. Through hydrophilic particle screening and hydrophobic groove modifying, the coalescence and sliding characteristics of droplets on the amphiphilic surfaces were improved. The incorporation of boron nitride (BN) nanoparticles further enhanced the surfaces' ability to harvest energy from condensation. To evaluate the water-harvesting performance of these amphiphilic surfaces, we utilized a real-time recording water-harvesting platform to identify microscopic weight changes on the surfaces. Our findings indicated that the inclusion of glass particles in hydrophobic grooves, combined with 1.0 wt.% BN nanoparticles, enhanced the water-harvesting efficiency of the amphiphilic surfaces by more than 20%.